Separation of constituents responsible for HIV infectivity inhibition and cytotoxicity. A. Cell cytotoxicity and anti-HIV activity associated with fraction E subfractions. Studies were performed with 30 μg/ml of each E subfraction. Shown are results from a representative experiment. B. Activities of E4 subfractions. Subfraction E4.7 demonstrated significant anti-HIV activity with modest levels of cytotoxicity. All E4 subfractions were assessed for cytotoxicity and anti-HIV activity at 10 and 100 μg/ml. C-D. Activities of E4.7 subfractions. C. Anti-HIV activity and cytotoxicity of subfractions at a concentration of 60 μg/ml. D. Dose-response curve of subfraction E4.7d demonstrated anti-HIV activity in the absence of detectable cytotoxicity. All cells in all experiments were exposed to equivalent concentrations of DMSO, the extract solvent. The findings are shown as percent control values (the cytotoxicity or number of HIV antigen-positive cells in the presence of the various concentrations of the subfractions divided by the cytotoxicity or number of HIV antigen-positive cells in the absence of the compound). The statistical significance of HIV-1 inhibition was evaluated by comparing the inhibition of HIV infection to cytotoxicity at the same concentration of the subfraction. *p = 0.05; **p = 0.001.